This research will be done primarily in Mexico at the Institute of Neural Biology, National University of Mexico in collaboration with Hugo Merchant-Nancy as an extension of NIH grant # 5R01-NS042778. Interval timing is a complex process that is not linked exclusively to any sensory modality and that is involved in a broad spectrum of behaviors, ranging from object interception and collision avoidance to musical performance and speech. However, there is a remarkable lack of information regarding the neurophysiological basis of temporal processing. The goal of the work outlined in this proposal is to gain understanding of the neural basis of interval timing in 100--1000 ms scale, and more specifically to investigate the role of the corticothalamic-basal ganglia circuit (CTBG) in this behavior. Although many pharmacological, lesion and imaging studies have implicated CTBG in temporal processing, the neural mechanisms of interval timing are still unknown. Our general thesis is that the production of time intervals depends on an internal clock whose neurophysiological mechanism is based on the distributed processing of information throughout the CTBG. In order to test these ideas, Rhesus monkeys will be trained in tasks that involve the production of single or multiple time intervals. The impulse activity of single cells will be recorded during task performance in 2 structures of the CTBG, namely, the supplementary motor area (SMA) and the putamen using a 7-microelectrode system. The data will be analyzed using uni-and multivariate statistical methods to correlate timing behavior and single cell and population activity. This will allow us to elucidate the role of CTBG components in temporal information processing, decipher the neural codes, and reveal the mechanism of the interval timing. [unreadable] [unreadable] [unreadable]